Lighting unit



J. A. ONEIL LIGHTING UNIT July 14, 1925.-

Filed March 9, 1923 2 Sheets-Sheet 1 IIHI His fibtorney sidewalk on one side of the street an Patented July 14, 1925.

OFFICE.

PAT

LAKES A. ON'EIL, OF LYNN, MASSACHUSETTS, ASSIGNOB' -TO GENERAL ELECTRIC COMPANY, A CORPORATION OF NEW YORK.

LIGHTING um.

' Application filed larch 9, 1928. Serial 0,823,828.

To all whom it may concern."

Be it known, that I JAMns A. ONEIL, a citizen of the United States, residing at Lynn, in the county of Essex, State of Massachusetts, have invented certainnew and useful Improvements in Lighting Units, of which the following is a specification.

My invention relates to lighting units and in articular to units adapted for lighting hig ways.

Heretofore lighting units for highways have been rovided in which a light source is located a ove a reflector having two win s so laced as to resemble an mverted Wit beams are produced, one extending in one direction alon the road and the other one in the opposite direction. One of these beams is roduced by one wing and the other one y the opposite wing of the V. However, if the lam is set to one side of the road or beyond t e sidewalk, the wings of the V must berotated about a vertical axis so as to throw the beams into the road. As a result of this rotation, the wings will se arate at the hinge, so to speak, leaving a ll sha ed crack or opening through which the lig t from the light source passes straight down to the ground without striking either side of the reflector. This of course, renders the beam less intense and consequently less effective. Although rotating the" wings operates to throw the beams into the road, nevertheless the beams that are thrown across the road lie with the major axis of the oval at an an le with the street, one end of the oval over appin tge t e other end overlapping the sidewalk on the opposite side. Thls last objection has been remedied'to some extent by other improvements, but these have not done away with the necessity of separatin the wings at the hinge. It 1s the object o my invention to overcome this objection by substitutlng or providing instead of reflectors, refractors of a certain character. These refractors are arranged V shaped with the wings separated above, like an upright V instead of below as an inverted V. These refractors I have provided with prismatic ribs running parallel to each other. If the light unit is to be located in the middle of the road the ribs are run parallel to the ground.

If the unit is located on one side of the a device of this character two oval street, the ribs will run parallel to each other but will all slant in one direction downward toward the street. If the unit is located on the opposite side of the street they also slant toward the street and the ribs on one side of the street will not be parallel to those on the opposite side of the street. With this arrangement the beam may be placed where it belongs in the road with the major axis of the oval, where the beam strikes the ound, running parallel with the center of the road. This can be accom lished without havin the re racting plates at the bin e.

It is also the object of my invention to provide other details of improvements to in crcase the efliciency and serviceability of a llghting unit of the above character.

to separate The means for accomplishing the fore oing and other useful ends are hereina r more fully set forth and claimed.

Referring to the accompanyin drawings: Fig. 1 shows a light unit in si e elevation partly in section on line 1-1, Fig. 2, with the refracting plates in place;

Fig. 2 is a bottom view of the same;

Fig. 3 "is a front view in elevation of the light unit. In this fi ure the hood that holds the refracting p ate is more clearly shown;

Fig. 4 is a front view .in elevation of one of the refracting plates in which the ribs are shown running parallel with the base of the plates;

Fig. 5 is an end view of the same;

Fig. 6 shows in top view the two refracting plates of the unit, Fig. 1, with the frame removed. In this figure, ovals are shown on either side representing the beams from the unit as they meet the ground;

Fig. 7 is an end view of the lates, Fig. 6;

Fig. 8 is a view similar to ig. 6, except that all of the ribs of one plate are shown slopin in one direction toward the base line, w ile the ribs of the opposite plate are shown slo ing in a different direction from the same ine;

Fig. 9 is an end view of the plates, Fig. 8 and is similar to Fig. 7;

Fig. 10 is a front view of Fig. 9- from ri ht to left;

ig. 11 is a front view of Fig. 9 from left to right and; r

Fig. 12 is an enlarged section of the glass plate showing the path of the light.

Referring more in detail to the accompanying drawings the top of the unit Fig. 1, is rovided with a paraboloidal refiector A, w ich reflector rests upon a hood-like frame B. The upper part of the frame is tubular and is cut on opposite sides in a downwardly sloping direction to resemble the letter V. These sloping sections are in the nature of windows opposite each other in which the refracting lates are mounted. These plates are made 0 lass, the interior faces of which are provi ed with suitable ribs which may extend parallel to each other and parallel to the base of the plate as in Fig. 4. This, of course, means that these ribs run parallel to the lower ed e of the hood as is the case when the unit 1s located in the middle of the road. These parallel ribs are shown not onl in Fig. 4 but also in Figs. 3, 2 and 6. As indicated in Fig. 2, a un1t is provided with two glass lates 2 and 3 one on each side of the hoo B. These two plates ap ear also in Figs. 6 and 7. As indicated .in ig. 6, the plate 2 produces a beam to the left which as it strikes the round forms an oval, indicated in the rawing by the oval F. Similarly the plate 3 throws a beam in the oppIosite direction which produces the oval G. he major axes of both these ovals lie in the same straight line along the middle of the road.

When the unit is laced on either side of the street instead of in the center, the ribs aremade to slope, as indicated in Fi s. 8, 10 and 11, toward the base of the p anes, i. e., toward the line where the two planes meet. If the unit is intended for the right side of the street looking in one directlon, the ribs'are made to slo e toward the street. If the unit is intended or the opposite side of the street, the ribs are caused to slope also toward the street which, of course, means that in either case the ribs slope toward a plane perpendicular to and along the middle of e street. With such provision, the unit may be shifted to one side or to the other of the line that coincides with the major axes of the ovals F and G and yet retain the ovals as indicated in Fig. 6 with their axes arallel and coincident with the center of t e street. Referring to Fig. 12, I show in this fi re the ribs on the inside of the plates. T ese ribs are prismatic in character. The rays of light, such as the ra 4,'come from above from the parabolic re ector and strike the surface 5 of the prismatic rib 6 at an angle such as to produce total reflection in the direction of the ray 7. All of the other prism surfaces 8, 9 etc., corres ending to the surface 5 run parallel to sur ace 5, and therefore each of these surfaces causes total reflection. As the rays, such as the re 7, emer from the outer surface 10 of t e glass p ate 11, they suffer an upward refraction as indicated in the drawing. However, the beam that passes out o the surface 10 slopes gradually down toward the surface of the road as indicated in Figs. 8 and 12. The up er surfaces 12 of the ribs are all para lel and horizontal and through these surfaces the rays pass into the glass. As indicated in Fig. 12, the inner border of the upper surfaces 12 may be made irregular in order to increase the diffusing effect upon the light. This construction is optional inasmuch as the inner surface 12 may be smooth.

In the construction of the unit the parabolic reflector A is secured to the hood B in any suitable manner. As shown in the drawing a source of. light C lies within the unit at or about the focus of the reflector A. This source of light maybe secured in any suitable manner to the reflector. The .reflector may be provided with an opening at the top through which the light socket may project as indicated.

With a unit constructed in accordance.

with my invention, the beams of light are thrown on the road without wasting any or little light beyond the sidewalks or ed es of the road. I avoid waste of light also y plreventing any rays from passing between he Furt ermore, by maintaining the prismatic ribs on the inside of the closure I minimize the ossibility of dirt and dust accumulating on t e ribs. It will be seen that with the construction shown in Figs. 8 through 11, the glass plates are retained closed and also slope toward each other and toward a lane at right angles to the longitudinal axle of the unit. Furthermore, the longitudinal axis of each of the prismatic ribs slopes also toward the said perpendicular plane. It will lass plates at the bottom of the unit.

be understood that the prismatic ribs may deviate from a straight line provided they have a common general direction. Furthermore, with the construction shown, it will be seen that the main beam projected bythe reflector A is divided into two diverging beams by said prisms, each beam having its axis in a separate axial plane, i. e. in a separate plane passing through the longitudinal axis of the unit.

What I claim as new and desire to secure by Letters Patent of the United States, is: 1. In a light unit, a series of lanes in which the rays from a beam of ight are changed in direction, said planes all sloping toward a line that lies across the beam, said planes divided into two, groups in each of which the planes run parallel to each other, the planes of one roup running in one di-' rect1on and the anes of the other group running in a di erent direction, each plane forming the side of'a'separate prism, all of the prismsin one oup having a face common to a ven sur ace, and-all of the prisms in the ot er group having a face common a line at right angles to'the major axis of the unit, and rismatic ribs in said planes for changing t e direction of the light from beam is divided into diverging beams, the

the unit,-sa1d prismatic ribs all sloping toward said line; 1

3. In a lighting unit a reflector and a light source for producing a beam along the axis of the unit, a V-shaped transparent closure for said unit in the ath of said beam with the sides of the V s oping toward the axis of the unit, and prismatic ribs in said sides for dividing the main beam into two diverging beams, the longitudinal axes of which slope toward a plane perpendicular to the longitudinal axis of the unit whereby the in said line.

axes of which beams lie in two separate axial planes of the unit.

4. In a light unit a source of light, a transparent element enclosing the light source having a series of rismatic elements each having a plane in w ich rays from the light source are changed in direction after entering the element, the axis of said elements all sloping toward a plane perpendicular to the longitudinal axis of the unit, said planes sloping with respectto the original direction of the changed rays at an angle less than the critical angle of total reflection whereby the beam is divided into diverging beams, the axes of which beams lie in two separate axial planes of the unit.

In witness whereof, I have hereunto set my hand this fifth day of March, 1923.

JAMES A. .ONEIL. 

